Accurate measurement of an antenna located at an earth station may require accurate measurement of a maximum and/or minimum values of cross-polarization isolation and/or a 1 dB gain compression point (P1 dB). The measurement of the cross-polarization isolation value and/or 1 dB gain compression point (P1 dB) may involve manually operating one or multiple spectrum analyzers to observe cross-polarization components and/or co-polarization components of a transmitted signal from an earth station under test (EUT). The cross-polarization isolation value may be calculated by manually measuring the carrier-to-noise ratio from the transmitted cross-polarization component and co-polarization component and performing a mathematical operation to determine the cross-polarization isolation value. The 1 dB gain compression point may be identified by increasing the input power level of the earth station under test (EUT) in 1 dB steps until an increase in the power of the transmitted signal becomes nonlinear with respect to the increase in the input power level. However, known techniques for computing and adjusting for cross-polarization isolation value and 1 dB gain compression point are labor and time intensive and thus fallible. Accordingly, there is a need for more accurate, reliable and efficient systems and techniques for verifying that earth station antenna are optimally aligned and calibrated.